I won't recommend to go up to 1mm, but 1.5mm should be fine if the structure supports it:

Walls under 3mm might be printable depending on your design's structure
In general, if your model is well supported (thicker walls weave in with thinner walls), or your thin walls are small relative to your structure (small rings and cufflinks), then you could print down to 1.5mm thin walls. To learn more about this, take a look at the next few design tips.